The present invention relates generally to fabrics and method of fabrication, and more specifically, to an improved fabric and method of fabrication having picot loops along both edges.
Woven fabrics, and more specifically narrow elastomeric fabrics are generally produced economically on needle looms. These looms include a weft insertion needle which inserts a weft thread from one side of the loom to the other wherein it is caught and bound by a knitting needle at the other edge. There are many ways of securing the weft thread at the knitted selvage including (a) knitting the weft thread with itself, (b) knitting a binder thread with itself and interlooping with the weft thread, (c) knitting the weft thread and binder thread together, (d) knitting two binder threads or a binder thread and a catch thread alternately upon themselves and interlooping with the weft thread, or (e) interlooping a binder thread with the weft thread and knitting the binder thread and the lock thread upon themselves. Other needle looms have included, instead of a knitting needle, a wire to engage the weft thread at the second edge during its return trip to the first edge, so as to prevent removal of the weft thread. Also, it should be noted that narrow elastomeric fabric may be produced by a shuttle loom, although the needle loom is faster and therefore more economical.
"Picot" is a word of art used to describe one of a series of small, ornamental loops extending from the edge of a fabric. Picot loops may be formed on the woven edge (the edge at which the weft needle is inserted) by a wire being horizontally inserted adjacent to this edge, as illustrated in U.S. Pat. No. 3,460,583, or by using a horizontal wire manipulated as a warp element in time relationship to the weft needle, as illustrated in U.S. Pat. No. 3,378,039. Picot loops may also be formed at the knitted edge by an element inserted vertically or horizontally to engage and retain the weft thread extended past the selvage edge as illustrated in U.S. Pat. No. 3,996,971 and United Kingdom Pat No. 1,452,191.
A double picot, or picot loops formed on both edges of a fabric, produced on a needle loom have two different types or styles of picot, one on each edge. At the woven edge, the picot loops extend substantially vertically and are known as a plain or common picot. On the knitted side, the picot loops extend diagonally because of the interlooping of the knitted binder thread with the picot loop. The diagonal setting of the picot cause it to flair, which is known as the "French picot." The diverse style of picot on the opposite edges of the fabric is undesirable from a marketing standpoint. Uniformity is produced on a shuttle loom in that common picots are formed since both edges are woven. Thus, if uniformity of picot on both edges of a fabric is desired, one has to settle with forming them on a shuttle loom which operates slower than the needle loom, thereby increasing the cost of manufacturing.
The knitted threads on the knitted edge of the fabrics are held secure against the edge warp thread by the weft loops. For a picot of, for example, five or more in a set, the knitted thread lies loose and possibly separated from the warp edge. This condition is undesirable. Similarly, the knitted thread forms what appears to be a cover of the exterior edge of the edge warp thread, whereas no cover is provided on the woven edge. Again, the dissimilarity between the woven and knitted edge is undesirable in certain applications.